It has long been recognized that it is advantageous to store hay in a compact state. To this end, pick-up balers have been known for many decades. In general terms, a pick-up baler is used to bale hay or straw directly from the windrow in the field. The hay is picked up by prongs and passed to the auger which pushes it to the feed prongs. The feed prongs, in turn, deliver the hay to the bale chamber on each stroke of a compressing plunger. The plunger compresses the hay to compact layers and the bales of hay are usually automatically tied with wire or twine. The advantage of square bales is in their relatively high degree of compactness which results in good economy of subsequent handling which may include untying the bales and dispensing same for the cattle as a fodder or feeding same into standardized processing devices such as a grinder-mixer. Modern grinder-mixers are usually mounted on a mobile frame and are typically brought to the field at which location fodder ingredients to be ground and mixed and including a substantial part of hay, are added into the machine and mechanically processed. The hay component is hand fed into the mixing device in the form of square bales. The feeding mechanism of the mixer grasps the bale and advances the hay further to the grinding/mixing mechanism of the device. Since the grinding and mixing device is usually of a high performance type, a continuous attention is required at the feeding of the hay.
While providing good economy for storage, the compacted square bales are relatively expensive to produce from the standpoint of energy required for compacting the material into the bales. The economy of forming bales of hay or the like material has been improved by switching to so-called round bales. The round bales are typically of a large diameter, often of about three meters in diameter. They are produced by what could generally be referred to as a winding or coiling operation without any attempts being made to compact the hay other than by the weight of the bale itself. The round bales have become very popular because they do not require special storage facilities. Their cylindric shape is suitable even for leaving the bales in the field and then dispensing same for the cattle as fodder, at a later time. However, if desired, the bales can be transported to a central storage place and various devices for handling the round bales have been proposed and are in operation, from the stage of forming the bales to the dispensing of same into shredding or other processing machines.
The disadvantage of the round bales is in their volume and in their weight, which make them unsuitable for manual handling. The relatively low density is usually compensated for by the speed of making the bales, which is much higher per volume unit than that of square bale making.
Among numerous devices for handling and processing round bales, U.S. Pat. No. 4,088,272 (Grillot) should be mentioned which shows a machine adapted to be towed behind a tractor for loading, shredding and feeding a cylindrical bale of hay. A discharge conveyor receives the hay from the auger and discharges it to the side of the machine for deposit in the windrow on the ground or into a feed bunk as the machine is moved by the tractor.
Another round bale dispensing device is shown in Canadian Patent No. 1,028,654 (Guichon). Here, the bale is supported by a series of supporting rollers which can be driven to "unwind" the bale and to dispense the thus formed material.
Another bale handling apparatus for processing round bales is described in Gibson U.S. Pat. No. 4,376,607, Bartolini U.S. Pat. No. 4,597,703, and in Vahikamp et al. U.S. Pat. No. 4,195,958.